The quality of randomized controlled clinical trials has a pivotal role in their external validity. There are no definite protocols to evaluate the quality of already published studies, whereas international guidelines for the preparation of randomized controlled trials are available. This review outlines some milestones in the development of guidelines for randomized controlled trials and presents the Revised Consort Statement which includes 22 items, sub divided into sections (title and abstract, introduction, methods, results and discussion) and a flow chart. The aim of this analysis is to provide clinical researchers with a valuable working tool. Finally, future guidelines for systematic reviews of randomized controlled studies are presented according to the Cochrane Collaboration model.